UNITED NATIONS, Feb 11 (Reuters) - Saudi Arabia, which is
leading air strikes against rebels in neighboring Yemen, has
warned the United Nations and international aid groups to
protect staff by removing them from areas near rebel military
bases, a letter seen by Reuters on Thursday said.

It was not immediately clear why Saudi Arabia issued the
warning and how many aid groups aside from the United Nations,
received the note. The Saudi U.N. mission was not immediately
available for comment.

A short note sent by the Saudi Embassy in London on Friday
said the intention was to "protect the international
organizations and their employees" presumably from coalition
airstrikes.

Saudi Arabia leads a coalition of nine Arab countries that
began a military campaign in March to prevent Houthi rebels,
whom it sees as a proxy for Iran, from taking complete control
of Yemen.

U.N. aid chief Stephen O'Brien acknowledged receipt of the
note in a Sunday letter seen by Reuters and said the
humanitarian community would continue to deliver aid across
Yemen impartially on the basis of need.

He reminded Saudi Arabia of obligations under international
humanitarian law to facilitate access for aid.

The Saudi mission to the United Nations responded on Monday
that Riyadh would "do its utmost to continue to facilitate and
support" humanitarian aid work in Yemen, while also clarifying
its request for U.N. and international aid workers to leave
areas close to Houthi bases for military operations.

"The coalition's request is consistent with its obligations
under international humanitarian law and, in no way, can be
misinterpreted to indicate any hindrance to humanitarian access
and the delivery of humanitarian assistance in Yemen," it said.

The U.N. Security Council is due to discuss the humanitarian
situation in Yemen on Tuesday at the request of Russia,
diplomats said.

The Houthis and their allies, forces loyal to former Yemen
President Ali Abdullah Saleh, accuse the coalition of launching
a war of aggression.

Nearly 6,000 people have been killed since the coalition
entered the conflict in March, almost half of them civilians.

U.N. sanctions monitors said in a report last month that the
Saudi-led coalition has targeted civilians with air strikes and
some of the attacks could be a crimes against humanity.

The panel of experts documented 119 coalition sorties
"relating to violations of international humanitarian law" and
said that "many attacks involved multiple air strikes on
multiple civilian objects."
(Reporting by Michelle Nichols; Editing by Cynthia Osterman)